As is known in the art, there is an increasing trend to include radar systems in commercially available products. For example, it is desirable to include radar systems in automobiles, trucks, boats, airplanes and other vehicles. Such radar systems are preferably compact and relatively low cost.
Many products impose relatively strict requirements on both the physical size and operational performance of the radar system. Such requirements make the design of radar systems for use in commercial products relatively challenging. Among the design challenges is the challenge to provide an antenna system which meets the design goals of being high performance, low cost and compact.
In automotive radar systems, for example, cost and size considerations are of considerable importance. Furthermore, in order to meet the performance requirements of automotive radar applications, (e.g. coverage area) multiple-beam antenna systems are typically required.
In one automotive radar system, a certain amount of resolution is desired in order to detect and track objects. To provide a system having acceptable resolution, an antenna system which produces multiple antenna beams can be used. One technique to increase the resolution of the system is to increase the number of antenna beams provided by the antenna system. Another approach to obtain additional resolution is to utilize relatively complex techniques such as monopulse or interferometer techniques to measure angle in a certain direction (e.g., azimuth angle). One problem with these techniques, however, is that they typically result in relatively high cost systems.